Paratrypanosoma Is a Novel Early-Branching Trypanosomatid
Paratrypanosoma Is a Novel Early-Branching Trypanosomatid
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DOI：
10.1016/j.cub.2013.07.045
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发表时间：
2013-09-23
期刊：
影响因子：
9.2
通讯作者：
Lukes, Julius
中科院分区：
文献类型：
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作者：
Flegontov, Pavel;Votypka, Jan;Lukes, Julius
动质体是一类广泛存在且重要的单细胞真核生物，其中许多是对动物（包括人类）具有毁灭性的寄生虫[1 - 3]。我们在库蚊（Culex pipiens）的肠道中发现了一种新的昆虫锥虫。基于甘油醛 - 3 - 磷酸脱氢酶和小亚基核糖体RNA的系统发育分析表明，这种寄生虫在自由生活的波豆虫（Bodo saltans）和以锥虫属（Trypanosoma）及其他锥虫为代表的专性寄生分支之间构成了一个独特的分支。从基因组草图序列数据中，我们鉴定出在这种新鞭毛虫、15种锥虫、波豆虫以及异叶足虫（Naegleria gruberi）之间共享的114个蛋白质基因，以及与基部动质体帕金虫属（Perkinsela sp.）共享的129个蛋白质基因。单个蛋白质系统发育以及串联比对分析表明，这个新物种（在此命名为混淆副锥虫新属，新种，Paratrypanosoma confusum n. gen., n. sp.）在锥虫科的基部以很高的支持率分支。因此，混淆副锥虫代表了长期以来人们一直在寻找的祖先自由生活的波豆虫和衍生的寄生锥虫之间缺失的一环。对混淆副锥虫基因组的进一步分析应该能为了解医学上重要的锥虫寄生现象的出现提供见解。
The kinetoplastids are a widespread and important group of single-celled eukaryotes, many of which are devastating parasites of animals, including humans [1-3]. We have discovered a new insect trypanosomatid in the gut of Culex pipiens mosquitoes. Glyceraldehyde-3-phosphate dehydrogenase- and SSU rRNA-based phylogenetic analyses show this parasite to constitute a distinct branch between the free-living Bodo saltans and the obligatory parasitic clades represented by the genus Trypanosoma and other trypanosomatids. From draft genome sequence data, we identified 114 protein genes shared among the new flagellate, 15 trypanosomatid species, B. saltans, and the heterolobosean Naegleria gruberi, as well as 129 protein genes shared with the basal kinetoplastid Perkinsela sp. Individual protein phylogenies together with analyses of concatenated alignments show that the new species, here named Paratrypanosoma confusum n. gen., n. sp., branches with very high support at the base of the family Trypanosomatidae. P. con fusum thus represents a long-sought-after missing link between the ancestral free-living bodonids and the derived parasitic trypanosomatids. Further analysis of the P. con fusum genome should provide insight into the emergence of parasitism in the medically important trypanosomatids.